Division of Physics and Applied Physics, School of Physical and Mathematical Sciences, Nanyang Technological University, Singapore, 637371, Singapore; Energy Research Institute @ NTU (ERI@N), 50 Nanyang Drive, Singapore, 637553, Singapore.
Small. 2014 Jan 29;10(2):300-7. doi: 10.1002/smll.201301009. Epub 2013 Aug 6.
Nanostructured carbon is widely used in energy storage devices (e.g., Li-ion and Li-air batteries and supercapacitors). A new method is developed for the generation of carbon nanoflakes on various metal oxide nanostructures by combining atomic layer deposition (ALD) and glucose carbonization. Various metal oxide@nanoflake carbon (MO@f-C) core-branch nanostructures are obtained. For the mechanism, it is proposed that the ALD Al2 O3 and glucose form a composite layer. Upon thermal annealing, the composite layer becomes fragmented and moves outward, accompanied by carbon deposition on the alumina skeleton. When tested as electrochemical supercapacitor electrode, the hierarchical MO@f-C nanostructures exhibit better properties compared with the pristine metal oxides or the carbon coating without ALD. The enhancement can be ascribed to increased specific surface areas and electric conductivity due to the carbon flake coating. This peculiar carbon coating method with the unique hierarchical nanostructure may provide a new insight into the preparation of 'oxides + carbon' hybrid electrode materials for energy storage applications.
纳米结构碳广泛应用于储能装置（如锂离子和锂空气电池以及超级电容器）。本研究提出了一种新方法，通过原子层沉积（ALD）和葡萄糖碳化相结合，在各种金属氧化物纳米结构上生成碳纳米片。得到了各种金属氧化物@纳米片碳（MO@f-C）核-支纳米结构。对于该机制，提出了 ALD Al2 O3 和葡萄糖形成了复合层。在热退火时，复合层发生碎裂并向外移动，同时在氧化铝骨架上沉积了碳。将分层 MO@f-C 纳米结构用作电化学超级电容器电极时，与原始金属氧化物或没有 ALD 的碳涂层相比，其性能得到了改善。增强的原因可归因于碳薄片涂层增加了比表面积和电导率。这种具有独特分层纳米结构的特殊碳涂层方法可能为制备用于储能应用的“氧化物+碳”混合电极材料提供新的思路。
